diff --git a/libc/include/sys/reboot.h b/libc/include/sys/reboot.h
index 156d947..5d9e1a7 100644
--- a/libc/include/sys/reboot.h
+++ b/libc/include/sys/reboot.h
@@ -55,6 +55,6 @@
  * Does not return on successful reboot, returns 0 if CAD was successfully enabled/disabled,
  * and returns -1 and sets `errno` on failure.
  */
-int reboot(int __cmd);
+int reboot(int __op);
 
 __END_DECLS